1. Filed of the Invention
The present invention relates to a method and/or a system and/or a device and/or a computer program product for analyzing a cellular wireless communication network of a first type in order to evaluate whether cell sites of the cellular wireless communication network of the first type are usable as cell sites for a cellular wireless communication network of a second type, and/or for evaluating parameters of the cellular wireless communication network of the second type, such as network performance, network dimensioning, optimization parameters, and the like.
2. Description of the Prior Art
In the last few years, an extension of wireless cellular communication networks all over the world has occurred. There exist several different network system solutions such as the European Global System for Mobile communication (GSM), the US equivalent thereof (GSM1900), North American TDMA (IS-54 or IS136), CDMAOne;(IS-95), Japanese Pacific Digital Cellular PDC, and the like, which are used in these wireless communication networks.
Additionally, there is also a constant further development of new network system solutions which are planned to supplement or to replace already existing networks. For example, the 3rd generation Universal Mobile Telecommunication System (3G UMTS), in which IS uses Wideband Code Division Multiple Access (WCDMA) technology is used. As a further example, the further development of CDMAOne, CDMA2000, can be mentioned here.
It should be noted that these communication network solutions, e.g. GSM, 3G UMTS, and equivalent network solutions, and the corresponding network elements and properties are commonly known to persons skilled in the art so that a detailed description thereof is omitted herein. Such detailed descriptions can be found in the respective network specifications and, for example, in “GSM Networks: Protocols, Terminology, and Implementation”, Gunnar Heine, Artech House mobile communication library Boston-London, 1999; “Introduction to 3G Mobile Communications”, Juha Korhonen, Artech House Mobile Communication Library, Boston-London, 2001; and “WCDMA: Towards IP Mobility and Mobile Internet”, Tero Ojanpera and Ramjee Prasad, Artech House Mobile Communication Library, Boston-London, 2001; “WCDMA for UMTS”, Harri Holma, Antti Toskala, John Wiley and Sons Ltd., 24 Jul., 2002; “UMTS Network: Architecture, Mobility and Services”, Heikki Kaaranen et al., John Wiley and Sons Ltd., 11 Jun., 2001; “GSM, GPRS and EDGE Performance—Evolution Towards 3G/UMTS”, T. Halonen, Javier Romero, Juan Melero, John Wiley and Sons Ltd., 23 Apr., 2002; “Radio Network Planning and Optimization for UMTS”, Jaana Laiho, Achim Wacker, Tomas Novosad, John Wiley and Sons Ltd., 29 Oct., 2001.
For the implementation of the new network system solutions, it is required to place the necessary communication equipment, such as stationary transceiver network elements and the like, at suitable locations. In other words, it is necessary to design, to found and to construct respective cell sites within the areas which are intended by a network operator to be covered with the new network system solution.
Due to the amount of already deployed sites in existing wireless communication networks, the high costs for the acquisition of new sites for a new system, and the complex and regulated processes for an acquisition of new sites in particular in urban areas, the implementation of such new network system solutions is difficult. Hence, one attractive and increasingly used option for network operators who already have an existing wireless communication network, such as a 2nd generation GSM network, and who want to deploy a new wireless communication network, such as a 3G UMTS network, is to reuse the already existing sites. Thus, costs can be saved and already available made sites can be further used for the new network solution.
As mentioned above, when a 3G UMTS network is considered as an example, a 3G UMTS Radio Access Systems uses WCDMA technology for the air interface. One characteristic of WCDMA technology is that a frequency reuse factor of 1 is used. This means that the same frequency for communication connections is used in adjacent cells (in contrast thereto, for example, in GSM systems a frequency reuse factor of e.g. 3, 4 or 12 is commonly used, i.e. the same frequency can be used in every third, fourth or 12th site, respectively). However, this WCDMA frequency reuse factor of one makes the interference existing in the system a critical point. Therefore, it is of utmost importance to select and configure the sites for a WCDMA based system in such a manner that the interference received and transmitted in the respective cells is as small as possible.
Thus, for the design of a new WCDMA system, in particular when it is planned to reuse existing cell cites of, e.g., a former cellular GSM communication network, an assessment of the interference situation is critical for a selection of the sites. The interference as a communication connection parameter is also essential for an estimation of capacity and quality properties of a network to be planned already in advance, namely for example in the form of a so-called other-to-own cell interference ratio.
Hitherto, a communication connection condition such as the interference situation in a network to be planned is assessed in two different ways. The first way is to simulate a network behavior with a software based radio network planning/simulating tool. The second way is to perform so-called drive tests in which test engineers drive through the network area and measure the behavior by means of special test equipment.
The first way provides the possibility to study the new network before it is actually deployed. However, for a usable test result, it is necessary to have an accurate propagation modeling and/or calibration, which can normally be achieved only by performing drive tests. However, a residual error after calibrating remains significant. On the other hand, the drive tests according to the above mentioned second way require a deployment of at least some physical parts of the new network or at least some test transmitters in the intended site locations. This results in high costs for the needed extra equipment and also for the test engineers, and is also time consuming.
In other words, conventional solutions for evaluating of network conditions and for estimating the capacity and quality of a planned 3G network are based on radio wave propagation predictions, which have the risk of being inaccurate, especially in hot spot areas where propagation conditions are almost impossible to simulate, such as in very dense urban areas, indoor areas or in the vicinity of high-rise buildings like in Manhattan or Hong Kong. Even when small-scale measurements like drive tests are used as a complement, there are still problems. Besides their costs, those drive tests can be normally performed only at a limited number of locations. Additionally, only outside and/or very limited inside measurements can be made. Furthermore, it is not possible to gain a realistic image about the behavior of actual service subscribers, such as usage of mobile/stationary terminals, calling from inside/outside, and the like.